The present invention relates to a roll forming machine.
The apparatus disclosed in Patent Document 1 is an example of a known roll forming machine. The roll forming machine disclosed in Patent Document 1 includes, as shown in FIG. 5, an upper roll 100 and a lower roll 200, which are rotationally supported on a pair of side walls 112, 113 provided on a base 110 via a pair of bearings 114 and a pair of bearings 115. The upper roll 100 and the lower roll 200 are formed by laminating disk-like cutters 102, 202 at predetermined intervals. As shown in FIGS. 6(a) and 6(b), cutting parts 102a, 202a project from the peripheral portion of the disk-like cutters 102, 202 at a predetermined pitch. The cutting parts 102a, 202a of the rolls 100, 200 mesh with each other. The meshing forms slits in a metal sheet W sandwiched between the rolls 100, 200.
Although a method for synchronously rotating the upper roll 100 and the lower roll 200 is not specifically disclosed in Patent Document 1, torque is typically transmitted between the upper roll 100 and the lower roll 200 via a non-illustrated gear mechanism.
Patent Document 2 discloses a plastic sheet forming roll apparatus, which includes a base embossing roll driven by a precision control electric motor and a driven embossing roll. A plastic sheet is sandwiched between the base embossing roll and the driven embossing roll so that the plastic sheet is embossed. In the apparatus of Patent Document 2, the rotational angle of each of the base embossing roll and the driven embossing roll is measured with a pulse generator, and the precision control electric motor is controlled such that the rotational angles match with each other.